Recent Advances in Chitosan-Based Composite Materials in Organic Transformations - A Review

Abstract

Abstract: Chitosan (CS) is a crustacean-derived bio-macromolecular base. Physico-chemical properties of CS resemble cellulose, and the chemical structure constitutes β-(1-4)-linked D-glucosamine and N-acetyl-D-glucosamine units. It has tunable characteristics such as molecular weight, degree of acetylation, and acetyl distribution. It is proven to be a very good support in making catalysts and functional materials. This article comprises the recently published articles using CS-based composites as heterogeneous catalysts in numerous chemical transformations of industrial relevance. In this connection, the CS-based composite materials have been successfully used as heterogeneous catalysts in a wide range of organic transformations including cycloaddition, trimethylsilylation, cyanation, Suzuki-Miyaura, Heck, Beckmann rearrangement, O-carboxymethylation, nitroarenes reduction, nucleophilic acylation (phenyl acetates from acid chlorides), Knoevenagel condensation, biomass valorization, P–O bond formation, imination, dipolar addition, and multicomponent reactions. The CS has also been used to prepare magnetic nanocomposite-based catalysts that showed easy separation and high reusability. This article is highly helpful in designing further chemical transformations where the role of the bio-polymeric base, CS may be critical.